Due to the widespread of personal computers and mobile phone terminals, an environment where everyone can use the Internet is being put in place. Web services via the Internet are also used widely. As an example, there is provided an auction site on which individuals are able to list their items for sale or win bids for items.
On conventional auction sites, sellers pay listing fees to the auction services to register their items for sale on the websites run by the auction services. Then, intending purchasers directly search the auction sites for desired items or seek items to purchase on affiliate sites introducing recommendable items, etc. If there are desired items, the intending purchasers will make bids.